Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Check wires to control module
- Connect test box to control module wiring harness. Refer to Test box, connecting for wiring test .
Vehicles with 80-pin control module
- Check for open circuits in wires between test box and connector according to wiring diagram.
Terminal 4 + socket 76
Terminal 7 + socket 53
Wire resistance: max. 1.5 Ω
Vehicles with 121-pin control module
- Check for open circuits in wires between test box and connector according to wiring diagram.
Terminal 7 + socket 111
Terminal 4 + socket 103
Wire resistance: max. 1.5 Ω
Vehicles with 154-pin control module
- Connect adapter cable (V.A.G 1598/39-1) to test box (V.A.G 1598/42).
- Check for open circuits in wires between test box and connector according to wiring diagram.
Terminal 1 + socket 40
Terminal 2 + socket 39
Wire resistance: max. 1.5 Ω
Continue for all vehicles
- Check wires for short circuit to each other, to vehicle Ground (GND) and to B+.
Specified value: ∞ Ω
If no malfunctions are found in wires:
- Replace Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) -J248-. Refer to Control module for Diesel-Direct Fuel Injection System, replacing .
- Generate readiness code.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.